Sheet feeding method and apparatus



Dec. 28, 1965 A. J. STAINES 3,226,107

SHEET FEEDING METHOD AND APPARATUS Filed June 26, 1963 5 Sheets-Sheet 1 FIG. I

ll I5 23 40 I BY ALFRED STAINES WM, M

ATTORNEYS Dec. 28, 1965 A. J. STAINES 3,226,107

SHEET FEEDING METHOD AND APPARATUS Filed June 26, 1963 5 Sheets-Sheet 2 FIG.6

INVENTOR B ALFRED J. STAINES M14 F|G.3 w

M RNEYS 1965 A. J. STAIN ES SHEET FEEDING METHOD AND APPARATUS 5 Sheets-Sheet 5 Filed June 26, 1963 FIG.I2

FIG."

INVENTOR.

ALFRED J. STAINES M14 00 ATTORN EYS Dec. 28, 1965 A. J. STAINES SHEET FEEDING METHOD AND APPARATUS 5 Sheets-Sheet Filed June 26, 1963 INVENTOR.

BY ALFRED J. STAINES 9 W ATTORNEYS United States Patent 3,226,107 SHEET FEEDING METHOD AND APPARATUS Alfred J. Staines, Shaker Heights, Ohio, assignor to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed June 26, 1963, Ser. No. 290,841 Claims. (Cl. 271-27) The present invention relates primarily to improvements in sheet handling methods and apparatuses and particularly to a sheet feeding method and apparatus in which the topmost sheet of a pile is separated from the pile and moved laterally of the pile to an advancing device which engages the sheet near the leading edge thereof and conveys the sheet away from the pile.

An object of the present invention is the provision of a new and improved method and apparatus for feeding sheets in overlapped relation from a pile, and wherein the front edge of each sheet fed is uniformly positioned relative to forwarding sucker members prior to engagement of the front edge of the sheet by the advancing device and wherein the forward portion of each sheet fed is supported by the pile and is tensioned by being pulled in the direction of feed by the sheets which are located in lapped relation relative thereto, and wherein a floating air stream is directed under each sheet to provide a film of air between the sheet and the pile to facilitate movement thereof relative to the pile and is terminated at about the time of forwarding.

A further object of the present invention is the provision of a new and improved method and apparatus for feeding the topmost sheet of a pile from the pile wherein a stream of high velocity floating air is utilized to assist in separating the topmost sheet from the pile and the rear or trailing portion of the sheet is held clear of the pile and wherein fluttering of the leading end of the sheet due to the floating air is minimized, thus facilitating engagement of the leading end of the sheet by the advancing device and providing for a relatively high sheet output.

A further object of the present invention is the provision of a new and improved method and apparatus for feeding sheets from a pile wherein the floating air stream is terminated at about the time the sheet is moved forwardly toward the advancing device.

A further object of the present invention is the provision of a new and improved sheet feeding apparatus wherein suction means engages the rear portion of the topmost sheet of a pile and moves the sheet forwardly and wherein the stream of floating air is terminated at about the time the sheet moves forwardly and substantially before the leading end of the sheet engages the ad vancing device so that the leading end of the sheet is not fluttering when it is to be engaged by the advancing device.

Another object of the present invention is the provision of a new and improved sheet feeding apparatus including means providing a stream of floating air and wherein the stream of floating air is terminated before the sheet is moved forwardly, thus providing for uniform operation regardless of the speed of operation of the feeder.

A further object of the present invention is the provision of a new, improved, simple, sheet feeding mechanism having a minimum of parts wherein cam actuated suction means is provided for raising the topmost sheet of a pile and for moving the sheet laterally of the pile and the suction for the suction means and a stream of floating air for assisting in separating the sheet from the pile are controlled from a single rotary valve means having a rotor mounted on a cam shaft, supporting the 3,226,137 Patented Dec. 28, 1965 ice cams for actuating movement of the suction means, and driven at the speed of the cam shaft.

A further object of the present invention is the provision of a new and improved valve for use in connecting sheet gripping suction members to a source of suction, and sheet floating air stream nozzle means to a source of air pressure and which includes a rotor member adapted to be mounted on a cam shaft supporting cams for moving the suction devices and be rotated at the speed of the cam shaft.

A further object of the present invention is the provision of a new, improved, highly simplified and compact valve mechanism for connecting suction means and air stream nozzle means to a source of suction and a supply of air, respectively, including a rotor member having an air chamber and a suction chamber constantly communicating with air and suction supply openings, respectively, and intermittently communicating with air and suction outlet openings, respectively, upon rotation thereof.

Further objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from the following detailed description thereof made with reference to the accompanying drawings forming a part of this application, in which:

FIG. 1 is an end elevational view of a portion of a sheet feeding apparatus embodying the present invention;

FIG. 2 is a top plan view of the portion of the apparatus shown in FIG. 1;

FIG. 3 is a fragmentary side elevational view, partly in section, of another portion of the sheet feeding apparatus embodying the present invention;

FIG. 4 is a schematic side view of the apparatus embodying the present invention and showing parts in one operative position;

FIG. 5 is a schematic side view of the apparatus, corresponding to FIG. 4, and showing the parts in a different operative position;

FIG. 6 is a schematic flow diagram illustrating the fluid system utilized in the apparatus;

FIG. 7 is an axial sectional view of a portion of the apparatus shown in FIG. 1 and taken approximately along section line 7-7 of FIG. 8;

FIG. 8 is a transverse sectional view taken approximately along the section line 8-8 of FIG. 7;

FIG. 9 is a transverse sectional view taken approximately along the section line 99 of FIG. 7;

FIG. 10 is a fragmentary axial sectional view of a portion of the apparatus shown in FIG. 9, taken approximately along section line 1010 of FIG. 9;

FIG. 11 is a side elevational view of an element forming a part of the apparatus shown in FIG. 7;

FIG. 12 is a side elevational view, partly in section, of another element forming a part of the apparatus shown in FIG. 7; and

FIG. 13 is a graph illustrating the timing of the operation of the various parts of the apparatus during an operative cycle.

The present invention relates primarily to a method and apparatus for separating the topmost sheet of a pile from the pile and moving the sheet laterally of the pile to an advancing means for feeding the sheet away from the pile, and wherein a stream of floating air is directed between the topmost sheet of the file and the next adjacent sheet of the pile to assist in separating the topmost sheet from the pile. The method and apparatus of the present invention have particularly utility in the feeding of sheets to a printing press, but may be used for feeding sheets to a variety of different processing machines or work stations.

As representing the preferred embodiment of the present invention, a sheet feeding apparatus is illustrated in the drawings for feeding sheets in an overlapped relation from a pile P. The pile P is supported on a pile support 11), which preferably comprises a conventional vertically movable plateform which raises as sheets are removed therefrom so that the topmost sheet of the pile is at approximately the same predetermined level regardless of the height of the pile. Moreover, the apparatus may include suitable and well known structure, not shown, for replenishing the supply of sheets to be fed without stopping the apparatus, thereby providing a continuous feeder.

The sheet feeding apparatus embodying the present invention preferably includes a sheet separating means including a first set of suction devices 11 which are operative to engage and grip the topmost sheet near the rear edge thereof, that is substantialy close to the edge which is the trailing edge when the sheet is fed so that the trailing edge does not droop' substantially and is maintained clear of the pile. The suction devices 11 are movable genearrly vertically for raising the topmost sheet from the pile to a second set of suction devices 12 forming a part of the sheet separating means which also engage and grip the sheet near its trailing edge. The suction devices 12 are movable generally horizontally and forwardly of the pile and receive the sheet from the first set of suction devices 11 and move the sheet to an advancing device 13, located forwardly of the pile, as shown in FIG. 3. The advancing device 13 engages the sheet near the leading edge thereof and conveys the sheet away from the pile. Before the trailing edge of a sheet clears the advancing device, other sheets are fed forwardly of the pile and under the trailing edge of the previously fed sheet, thereby providing an overlapped sheet stream. While the apparatus, as described above, preferably includes two sets of suction devices 11 and 12, a single set of suction devices having a substantial increment of movement in the vertical direction and in the horizontal direction may be used for conveying the sheets to the advancing device 13 and providing the overlapped sheet stream.

Each of the suction devices 11 includes a vertically movable sheet raising sucker member 15 which engages the topmost sheet and grips the sheet by suction. As best shown in FIG. 1, a suitable mechanism is provided for moving each sucker member 15 generally vertically and includes a conventional linkage 16, actuated by a cam member 17. The linkage 16 is connected to its associated sucker, member 15 and is effective to raise the sucker member 15 as the. cam member 17 rotates. A suitable spring means effects lowering the sucker member 15 under the control of the cam member 17, as is well understood in the art. The specific detailed construction of the linkage 16 is not important to an understanding of the present invention and will not be described in detail, it being understood that any suitable linkage arrangement may be used and reference is made to United States Patent No. 2,108,702 which illustrates such a suitable linkage.

The cam members 17 for actuating movement of the sucker members 15 are mounted upon a cam shaft 18 for rotation therewith; however, the cam members 17 may be moved axially of the cam shaft 18 for adjustment purposes. The cam shaft 18 is rotatably supported by side frame members 19 and 20 of the sheet feeding apparatus, and is rotated in any suitable manner, as from the drive forthe printing press or processing machine to which the sheets are fed. In the preferred embodiment the drive for rotating the cam shaft 18 is from the printing press to which the sheets are fed and is designated 18a.

The operating linkage 16 and the cam 17 for actuating each sucker member 15 are located in a housing 21 suitably supported between the side frame members 19 and 20. Within each housing 21 there is also located a suitable linkage and cam mechanism 22 for operating a conventional presser foot 23 which engages the next to the 4 topmost sheet in the pile to hold it down while the topmost sheet in the pile is raised by the sucker members 15. Each presser foot 23 remains in engagement with the sheet until the sucker members 15 move down to engage the sheet at which time the presser foot moves upwardly and rearwardly of the pile to permit the rear portion of the sheet to be raised by the raising sucker members 15, and the presser foot then moves downwardly to engage the next sheet and hold it in position, while the topmost sheet is raised and moved forwardly.

The suction devices 11, presser foot mechanism, and housing 21 are adjustable along the cam shaft 18 and may be manually moved along the cam shaft toward and away from each other upon loosening of suitable clamping bolts which secure the suction devices in position between the frame members 19 and 20. Upon loosening of these bolts, as is well known, the suction devices 11 may be adjusted for handling different width sheets.

Each of the forwarding suction devices 12 includes a pair of sheet forwarding sucker members 25 which grip a sheet by suction. The sucker members 25 are preferably of the type which draw back after gripping the sheet and before moving it forward. Suitable means for moving the sucker members 25 generally forwardly of the pile is provided including a shaft 26 which extends between the side frame members 19 andZtB and on which the sucker members 25 are adjustably secured. The shaft 26 is rotatably supported by the side frame members 19 and 20 and is rotated in the side frames to move the sucker members 25 forwardly by a suitable cam 27 and linkage 28 actuated by the cam 27 and forming part of the means for moving the sucker members. The cam 27 is mounted on the cam shaft 18 and is rotatable therewith and the linkage 28 is operatively connected to the shaft 26 to rotate the shaft 26 and move the sucker members 25 between their full line positions shown in FIGS. 3 and 4. The linkage 28 may take various conventional forms and the specific construction thereof will not be described herein in detail, since the specific details thereof are not important to an understanding of the present invention. United States Patent No. 2,108,702, aforementioned, illustrates such a suitable linkage.

The sheet feeding apparatus embodying the present invention further preferably includes a pair of comber mechanisms 30. Each comber mechanism 30 includes a comber wheel 31, which engages the top of the pile at opposite sides thereof, and a drive for rotating the comber wheel 31 so as to separate the outer edges of the sheets in the pile and raise the outer edge portions of the sheet to be engaged by the sucker members 15, as is well known. A suitable cam operated linkage arrangement is provided for raising the comber wheels 31 out of engagement with the pile at the proper time in the cycle of operation and a suitable spring means controlled by the raising cam effects lowering of the comber wheels 31 into engagement with the pile prior to the lowering of the sucker members 15 to comb up the sheets for the latter.

Also preferably included in the sheet feeding apparatus is a means for directing a stream of separating air at the: edges of the uppermost sheets in the pile to, as is well known, ruffle the edges of the sheets and assist in separating the topmost sheet from the stack. The means for directing the stream of separting air includes air nozzles 35, 36 located adjacent opposite sides of the pile and positioned to direct the air against the rear edges of the uppermost sheets in the pile. The separating air flows through the nozzles 35, 36 while the comber wheels 31 comb the edges of the pile, and the flow is terminated at about the time the raising sucker members 15 grip the sheet.

The apparatus further includes means for directing a stream of floating or forwarding air at preferably high velocity between the topmost sheet of the pile and the next adjacent sheet in the pile toward the forward end thereof to assist in the separating of the topmost sheet from the pile and to facilitate moving the sheet forwardly. The floating air functions to provide a film of air between the topmost sheet and the pile to thereby separate or break the forward end of the topmost sheet from the next adjacent sheet so as to facilitate movement of the sheet forward by sucker members 25.

The means for directing the floating air toward the forward end of the sheet comprises floating air nozzles 40, 41 located to direct the air between the topmost sheet and the next adjacent sheet in the pile and toward the forward end thereof. The stream of floating air is initially directed under the topmost sheet to provide a suflicient flow to suitably separate the forward end of the topmost sheet from the pile before the sheet is moved forwardly and to provide the above mentioned film of air so as to minimize frictional drag of the sheet being forwarded on the next sheet in the pile. In the preferred embodiment the floating air stream is initiated while the sheet raising suckers are moving upwardly. The floating air stream when initiated provides the above noted air film and separates the sheet being fed from the top of the pile, as shown in FIG. 4.

The flow of floating air is terminated substantially before the sheet is engaged by the advancing device 13 and about the time of forwarding of the sheet so that the leading edge of the sheet will not be fluttering and flapping when the sheet reaches the advancing device and is to be engaged thereby. Preferably, the flow is terminated after the sheet forwarding sucker members 25 have gripped the sheet and before the sucker members 25 begin to move the sheet forwardly toward the advancing device 13, as will be described in more detail hereinbelow. However, the air may be terminated shortly after the sheet forwarding movement is initiated and within about 10 of cam shaft rotation after the forwarding sucker members 25 initially move forward.

After the floating air is terminated the forward end portion of the topmost sheet drops to the pile, as shown in FIG. 5, but a film of air will remain between the sheet and the top of the pile to facilitate the forward movement of the sheet gripped by the forwarding suckers 25. In a stream feeder such as illustrated in the drawing, the sheet gripped by the suckers 25 will be lapped, at this time, by the sheets which had been separated immediately prior to that gripped by the suckers 25. These sheets which overlap the gripped sheet are being pulled by the advancing device 13. Apparently, the dragging of the sheets by the device 13 over the sheet gripped by the suckers 25, causes tensioning of the sheet gripped by sucker member 25 to straighten the sheet somewhat and cause the forward edge thereof to be disposed in a predetermined position relative to the forwarding suckers 25 prior to the engagement of the front edge with the advancing device 13. This tensioning is facilitated by the above noted film of air. In the preferred and illustrated embodiment the forwarding air is terminated in advance of the time that the forwarding suckers start forward. When this is done, there appears to be sufficient time after the termination of the forwarding air for the sheet to settle to the top of the pile and for the sheet to be tensioned prior to the time that it arrives at the advancing device 13, regardless of the speed of operation of the press.

While the dragging of the previously separated sheets over the sheet being advanced by the forwarding suckers 25 appears to be advantageous in tensioning the sheet being handled by the forwarding suckers 25, advantages flow from termination of the forwarding air in accordance with the basic concept of the present invention even though the frictional drag of the previously separated sheet is not present. Thus in a sheet feeder as distinguished from a stream feeder, the termination of the forwarding air at about the time the forwarding sucker starts forward or at least within 10 of the feeder cycle of the time that the forwarding suckers start forward thereby minimizing the fluttering of the sheet and minimizing problems of causing the sheet to be improperly taken by the advancing device 13.

The advancing device 13 which feeds the sheets away from the pile may be of any conventional construction and preferably includes a pair of sheet engaging forwarding rolls 42, 43 having a sheet engaging nip located forwardly of the pile P and preferably is in the same horizontal plane as the top of the pile. A feed plate 45 functions to guide the leading end of a sheet upwardly and forwardly into the nip formed by the rollers 42, 43 in the event the leading end drops downwardly when fed forward. The feed plate 45 is pivotally supported at the forward end of the pile P, and has a first position, shown in FIG. 3, wherein it extends vertically and functions as a stop for the leading edge of the sheets in the pile and a second position, shown in FIG. 4, wherein it extends at an angle to the horizontal and approximately tangentially to the feeding rollers 42, 43 and functions, as above mentioned, to guide the leading end of a sheet into the nip formed by sheet feeding rollers 42, 43. A suitable linkage mechanism 46 is provided for pivoting the feed or guide plate 45 between its positions.

As above mentioned, the sheet floating air stream is terminated preferably before the sheet is moved forwardly by sucker members 25, and therefore the sheet floating air is off when the leading edge of a sheet begins moving up feed plate 45 and when it reaches rollers 42, 43 and is engaged in the nip thereof, as illustrated in FIG. 5. Thus, the leading edge of the sheet does not I flutter or flap due to the floating air stream when it is to be engaged by the rollers 42, 43, and the leading edge of the sheet is therefore readily engaged in the nip of the feeding rollers 42, 43. Thus, the apparatus can be operated at an increased speed thereby increasing the output thereof over conventional feeding apparatus.

According to the present invention, the sheet floating air stream, the separating air stream, and the suction for sucker members 15 and 25 are all controlled by a single rotary valve means 50, which connects the floating air nozzles 40, 41 and separating air nozzles 35, 36 to a source of air and connects the sucker members 15 and 25 to a source of suction at the proper time in the cycle of operation of the apparatus. The valve means 50 is located, preferably, centrally of the apparatus and above the sucker members 15, 25 and air nozzles 35, 36 and 40, 41, and is supported on hollow shaft members fixedly supported in the side frame members 19, 20.

The valve 50 includes a housing and a rotor member 56 closely fitting inside the housing 55 and which is keyed to the cam shaft 18 and rotates at the same speed or number of revolutions per minute as the cam shaft 18. The housing 55 includes three housing members 57, 58, 59 having axially extending openings therethrough. The members 57, 58, 59 are suitably secured together by screws 59a and are positioned axially adjacent each other with the opening therethrough in alignment. The members 57 and 59 are, generally speaking, annular and form the opposite ends of the housing 55 while the member 58 is positioned between the members 57, 59 and has an irregular shape and constitutes a bracket member which cooperates with the aforementioned hollow shafts to support the valve means.

The housing 55 also includes a sleeve member 60 ex tending through the aligned openings in the housing members 57, 58, 59 and fixed therein. The sleeve member 60 has axially spaced inlet openings 61, 62 therein communicating the exterior of the sleeve 60 with the interior of the sleeve within which the rotor member 56 is ro tatably supported. The inlet opening 61 in the sleeve member 60 is a suction inlet opening and communicates with a passageway 63 formed in housing member 57 and connected to a source of vacuum, and the inlet opening 62 is an air inlet opening and communicates with a passageway 64 in bracket housing member 58 which communicates with a supply of air.

The sleeve 60 has a pair of circumferentially spaced air outlet openings 65, 66 (see FIG. 8) located in the right end portion thereof as viewed in FIG. 11, which are alternately connected to the air inlet opening 62 through the rotor member 56 upon rotation thereof, as will be described in detail hereinbelow. The outlet opening 65 communicates with a separating air outlet chamber 67 formed in the housing member 59, as illustrated in FIG. 8. A first separating air nipple 68 supported on housing member 59 communicates with the chamber 67 and an axially extending air passage 70 provided in housing 55 communicates with the chamber 67 and with a second separating air nipple 71 supported on housing member 57. The separating air nipples 68, 71 are connected through suitable conduits, shown schematically in FIG. 6, to the separating air nozzles 35, 36, respectively. From the above description it can be seen that when air is directed into air chamber 67 air is directed through the separating air nozzles 35, 36.

The air outlet opening 66 in the sleeve member 60 communicates with a floating air outlet chamber 74 formed in the housing member 59. A first floating air nipple 75 supported on housing member 59 communicates with the chamber 74, and an axially extending air passage 76 also communicates with chamber 74 and with a second floating air nipple 77 supported on housing member 57. The floating air nipples 75, 77 are connected through suitable air conduits shown schematically in FIG. 6, to floating air nozzles 40, 41, respectively. From the above description it can be seen that when air is directed into air outlet chamber 74 air is directed to the floating air nozzles 40, 41.

As stated above, the rotor member 56 connects the air inlet opening 62 to the air outlet openings 65, 66 during rotation thereof to provide a stream of separating air and floating air at the desired time, as described above. To this end the rotor member 56 has an axially and circumferentially extending air chamber 80. The air chamber 80 at one end constantly communicates with the air inlet opening 62 through the provision of an annular groove or chamber portion 81 which extends circumferentially and completely around the rotor member 56. At its other end the air chamber 80 includes an annular ring-shaped chamber portion 82 which is separated from the sleeve member 60 by an axially extending flange portion 83 of the rotor member 56.

The portion 83 of the rotor member has an opening 85 therein which communicates the chamber portion 82 with the exterior of the rotor member 56. The opening 85 is positioned so as to be opposite air outlet openings 65 and 66 during different times during the rotation of the rotor 56. When opening 85 lies opposite opening 65, as shown in FIG. 8, air is directed into separating air outlet chamber 67 and in turn separating air nozzles 35, 36 as described above. When opening 85 lies opposite air outlet opening 66 air is directed to floating air outlet chamber 74 and to floating air nozzles 40, 41, as described above.

As mentioned above, the valve means 50 also connects the sucker members 15, 25 to a source of suction, and the sleeve member 60 has a first suction inlet opening 61. The sleeve member 60 has a second suction inlet opening 88 located substantially diametrically from the suction inlet opening 61, as shown in FIG. 9. The inlet opening 88 communicates with a suction chamber 90 in the housing member 57 which in turn communicates with an annular circumferentially extending groove 91, shown in clot-dash lines in FIG. 9 and formed in member 57 and communicating with the suction chamber 63. Thus suction is always applied to suction inlet openings 61 and 88 in the sleeve member 60.

The sleeve member 60 has a pair of suction outlet openings'93, 94 which are spaced circumferentially of the sleeve member 60 (see FIG. 9). The suction outlet opening 93 communicates with a suction outlet chamber 95 in the housing member 57 which communicates with a first raising sucker nipple 96 supported on housing member 57. The chamber 95 also communicates with an axially extending suction passage 97 formed in the housing 55. The suction passage 97 in turn communicates with a second raising sucker nipple 98 supported on housing member 59. The raising sucker nipples 96, 98 communicate through suitable conduit with the raising sucker members 15, as shown schematically in FIG. 6.

The suction outlet opening 94 in the sleeve member 60 communicates with a suction outlet chamber 100 formed in housing member 57 which in turn communicates with a first forwarding sucker nipple 101 supported by the housing member 57. The chamber 100 also communicates with an axially extending suction passage 102 formed in housing 55 which in turn communicates with a second forwarding sucker nipple 103 supported by housing member 59. Forwarding sucker nipples 101, 103 are connected through suitable conduits to the forwarding sucker members 25, as shown schematically in FIG. 6.

As noted above, rotor member 56 is eflFective to connect the suction outlet openings'93, '94 to the source of suction. To this end, rotor member 56 has a suction chamber 107 which is defined by a circumferentially extending slot in the rotor member 56 and extends approximately 180 around the rotor member 56. As the rotor member 56 rotates the suction chamber 107 aligns with the suction inlet openings 61, 88 and the suction outlet openings 93, 94 to apply suction to the suction outlet openings. Because of the relative sizes of the inlet openings 61, 88 and the chamber 107, the chamber 107 communicates at all times during its rotation with either suction inlet opening 61 or 88 or both. Thus the chamber 107 constantly has a suction applied thereto. Therefore, when suction chamber 107 communicates with outlet opening 93 suction is applied to suction outlet chamber 95 and in turn to the raising sucker members 15, as described above. When suction chamber 107 communicates with outlet opening 94 suction is applied to suction outlet chamber 100 and in turn to the forwarding sucker members 25, as described above.

The valve means 50 preferably includes means for breaking the suction in the sucker members 15 and 25 when the sheet is to be released therefrom. This means includes separate fluid passages for connecting the suction outlet openings 93, 94 in the sleeve member 60 to the air chamber 80 of the rotor member 56. This causes air to flow into the suction chambers 95, 100, respectively, and thus breaks the suction therein and the suction in the sucker members 15, 25, respectively. The fluid passage for communicating the opening 93 with the air chamber 80 includes an axially extending extension 110 of opening 93. The extension 110 communicates with the interior of the sleeve member 60 through a radially extending passage portion 110a. A radially extending passage 111 formed in the rotor member 56 communicates with passage portion 110 during rotation of the rotor 56. The passage 111 communicates in turn with a substantially axially extending passage 112 which in turn opens into air chamber 80. Thus, when passage 111 communicates with passage portion 110a, air is directed into opening 93 in the sleeve 60 and then into sucker members 15 to break the suction therein.

The means for breaking the suction in the sucker members 25 is similar to that described above in connection with sucker members 15 and the fluid passage connecting the suction outlet opening 94 to the chamber 80 includes an extension 115 of opening 94. The extension 115 communicates with the interior of the sleeve member 60 through a radially extending passage portion 115a. A radially extending passage portion 116 in the rotor member 56 and an axially directed passage portion 117 communicating with chamber 80 and passage 116 connect chamber 80 with the passage portion 115a. When the rotor member 56 rotates and at the proper time in the cycle of operation, the passage 116 communicates with passage 115a and thus directs air to the opening 94 and in turn to the forwarding sucker members 25.

The operation of the above described apparatus and method performed thereby can be better visualized by reference to the graph constituting FIG. 13 of the drawings. Referring now to FIGURE 13, the vertical movement of the presser foot 23 is depicted by the line 120, While the vertical movement of the comber wheels 31 is depicted by the line 121. The vertical movement of the raising sucker members 15 and the horizontal movement of the forwarding sucker members 25 is indicated by the lines 122 and 123, respectively. The line 124 designates the horizontal position of the front edge of the sheet when the sucker members 25 receive the sheet. The dotted lines 125 illustrate when the separating air is being directed through the separating air nozzles 35, 36 and the dotted line 126 illustrates when the sheet floating air is being directed through the floating air nozzles 40, 41. The dotted lines 127 and 128 indicate when the suction is applied to the raising sucker members 15 and the forwarding sucker members 25, respectively.

Referring more specifically to the movement of the various parts, at zero degrees of rotation of the cam shaft 18 as indicated on the graph the presser feet 23 are in engagement with the topmost in the pile, the comber wheels 31 are moving downwardly to engage the sheet, the separating air stream is on, the raising sucker members 15 are moving downwardly to grip the sheet, and the forwarding sucker members 25 are moving forwardly of the pile. The comber wheels 31 then engage the pile and ruffle the pile to separate the outer edges of the sheets in the pile, as discussed above. The separating air stream assists in this separation, and separating air is directed through the nipples 68 and 71 to the separating air nozzles 35 and 36, as described above for a period of time as indicated by the length of the line 125.

The separating air is terminated and the comber wheels and presser feet move upwardly at about the time the raising sucker members 15 engage the topmost sheet in the stack. The suction, as indicated by the line 127, is applied to the raising sucker members 15 immediately before they have reached their lowermost point and engage the topmost sheet and the sheet is thus gripped by sucker members 15. The raising sucker members 15 then begin rising, at which time the comber wheels 31 and presser feet 23 have moved so as to not interfere with raising of the sheet by the sucker members 15.

While the raising sucker members 15 raise the sheet, the forwarding suckers 25 move into positlon indlcated 123a on line 123 to receive the sheet from the ra s ng sucker members 15, preferably just prior to the raismg sucker members 15 reaching their highest POIDt and when the forwarding sucker members 25 are 1n position to receive the sheet, the floating air stream is dlrected under the sheet, as described above.

Suction is applied to the forwarding sucker members 25 at about the time when the floating air stream 15 1111- tially directed through the nozzles 40 and 41 and thus sucker members 25 grip the sheet. After the sucker members 25 grip the sheet, suction to the raising sucker members 15 is broken. Subsequently, the stream of floating air begins to cut off and then the forwarding sucker members 25 pull back as indicated by portion 123]) of the line 123 and then begin to move the sheet forwardly into the nip of the rollers 42, 43 of the advancing device 13. The stream of floating air, as in the preferred embodiment, starts to cut off before the sheet begins its forward movement and is completely terminated before the sheet moves forward so that the leading end of the sheet rests on the pile with a film of air thereunder and when the sheet is moved forwardly the leading end does not flutter or flap due to the floating air stream when it is to be engaged by the advancing device 13. In the event that the stream of floating air is terminated after the forwarding suckers begin moving the sheet forwardly, as noted above, the leading edge of the sheet will be moved ap proximately eight percent of its total movement by the forwarding suction members toward the nip of the for warding rolls. This can be readily seen from FIG. 13. The suction for the forwarding sucker members is broken when the sheet is engaged in the nip of the rollers 42, 43 of the advancing device 13 while the sheet is being moved forwardly of the pile by sucker members 25. The comber wheels 31 and presser feet 33 move into engagement with the next sheet to be fed and the separating air stream is initiated.

The particular timing for the various operating mechanisms, as illustrated in the graph constituting FIG. 13, is provided by the particular shape of the cam members for actuating movement of the operating mechanisms and by the position of the rotor member 56 relative to the cam members. The particular shape of the cam members and this particular positioning of the rotor member rela tive to those cam members is Well within the domain of one skilled in the art and this relative positioning and the various shapes of the cam members have not been shown in specific detail in view of this fact.

While the preferred embodiment of the present invention has been described hereinabove in considerable detail, it should be understood that certain modifications, changes and adaptations thereof may be made by those skilled in the art to which it relates and that it is hereby intended to cover all such modifications, adaptations and changes falling within the scope of the appended claims.

Having described my invention, I claim:

1. A sheet feeding method for feeding the topmost sheet of a pile from the pile comprising the steps of raising the rear end portion of the topmost sheet of the pile to separate the rear portion of the sheet from the pile, directing a stream of floating air under said topmost sheet and toward the forward end thereof while the rear portion of the sheet is separated from the pile, engaging the rear end portion of the sheet by forwarding suction members, feeding said sheet forwardly of said pile by moving said forwarding suction members in a forward direction after the stream of floating air is initiated, maintaining the rear portion of the sheet clear of the pile as it is moved forwardly, engaging the forward end of the sheet after the forward end of the sheet has been fed forwardly of the pile to a predetermined location by movement of said forwarding suction members for feeding away from the pile, and terminating the flow of said floating air toward said forward end of the sheet before the forward end of the sheet is moved by said forwarding suction members 8% of the total forwarding movement of the sheet by said forwarding suction members.

2. A sheet feeding method for feeding the topmost sheet of a pile from the pile comprising the steps of raising the rear portion of the topmost sheet of the pile to separate the rear portion of the sheet from the pile, directing a stream of floating air under said topmost sheet when the rear portion is separated from the pile to provide a film of air between the forward end portion of the sheet and the pile, moving said sheet forwardly of said pile after the floating air stream is initiated, guiding the leading end of the sheet as it is moved forwardly into position to be engaged for feeding from the pile, engaging the forward end of the sheet after the forward end has been fed forwardly of the pile for feeding of the sheet away from the pile, and terminating the flow of said floating air before the sheet begins to move forwardly of the pile.

3. A sheet feeding method for feeding sheets in an overlapped relation from a pile comprising the steps of raising the rear portion of a first sheet from the pile, directing air through floating air nozzle means under said first sheet, feeding said first sheet forwardly of said pile after air is directed thereunder, maintaining the rear por tion of said first sheet clear of the pile as it is moved forwardly, engaging the forward end of said first sheet after it has been fed forwardly of the pile for feeding of the sheet away from the pile, terminating said flow of air under said first sheet at about the time the sheet is initially moved forwardly of the pile, raising the rear portion of a second sheet from the pile, directing a flow of floating air through the nozzle means and under said second sheet, terminating the flow of floating air under said second sheet at about the time it is initially moved forwardly, feeding said second sheet forwardly under the rear portion of said first sheet, feeding the first sheet away from the pile and relative to said second sheet and tensioning said second sheet due to the frictional drag between said first sheet and said second sheet to position the forward edge of the second sheet at a predetermined location.

4. A sheet feeding apparatus for feeding the topmost sheet of a pile from the pile comprising first sucker members operable to grip portions of the topmost sheet near the rear edge thereof and to move generally vertically to raise the rear end portion of said sheet, second sucker members operable to grip the sheet near the rear edge thereof and move the sheet forwardly of said pile after it has been released by said first sucker members, sheet advancing means located forwardly of said pile for engaging a sheet moved forwardly by said second sucker members near the leading end thereof and operable to feed the sheet away from the pile, means for providing a flow of floating air directed under said topmost sheet and to ward the forward end thereof to provide a film of floating air between the topmost sheet and the pile prior to movement of the sheet forwardly, and means for terminating said flow of floating air toward said forward end of said topmost sheet before the sheet is moved forwardly by said second sucker members.

5. A sheet feeding apparatus for'feeding the topmost sheet of a pile from the pile comprising, first suction members operable to grip portions of the topmost sheet, drive means including a first cam means for moving said first suction members generally vertically to raise portions of the sheet, floating air nozzle means for directing a stream of floating air under said topmost sheet, second suction members adapted to grip the sheet and receive the sheet from said first suction members, drive means including second cam means effective to move said second suction members generally forwardly of the pile to move the sheet forwardly of said pile, a cam shaft supporting said first and second cam means to effect rotation thereof, sheet advancing means located forwardly of said pile for engaging a sheet moved forwardly and operable to feed a sheet I away from the pile, and valve means for connecting and disconnecting said floating air nozzle means to a supply of air before said second suction members move said sheet forwardly and including a housing member having air inlet and outlet openings adapted to be connected to a supply of air and the floating air nozzle means, respectively, and a rotor member supported by said cam shaft and rotatable at the speed of said cam shaft to connect said air inlet and outlet openings in said housing member and to control the timing of the operation of said stream of floating air.

6. A sheet feeding apparatus for feeding the topmost sheet of a pile from the pile as defined in claim-5, wherein said rotor member has an air chamber constantly communicating with said air inlet opening and means providing a passageway for communicating said air chamber with said air outlet opening during only a portion of the rotation of said rotor member.

7. A sheet feeding apparatus for feeding the topmost sheet of a pile from the pile comprising, first suction members operable to grip portions of the topmost sheet near the rear edge thereof, cam actuated means for moving said first suction members generally vertically to raise th rear end portion of the sheet, second suctionmembers operable to grip the sheet near the rear edge thereof after it has been raised by said first suction members, cam actuated means for moving said second suction members forwardly of said pile to move said sheet forwardly of said pile, sheet advancing means locate-d forwardly of said pile for engaging a sheet moved by said second sucker members near the leading end thereof and operable to feed the sheet away from the pile, floating air nozzle means for directing a stream of floating air under said topmost sheet to raise the forward end of said topmost sheet so that it may be moved by said second suction members into position to be engaged by said advancing means, and a valve means for connecting said suction members and said floating air nozzle means to a source of suction and a supply of air, respectively, including a housing member having air inlet and outlet openings communicating with the supply of air and said air nozzle means, respectively, and suction inlet and outlet openings communicating with the source of suction and the suction members, respectively, a rotor member rotatable in said housing and having a suction chamber constantly communicating with said suction inlet opening, said suction chamber being located so that upon rotation of said rotor it aligns with said suction outlet openings, said rotor member also including an air chamber constantly communicating with said air inlet opening and means providing a passageway for communicating said air chamber with said air outlet openin during a portion of the rotation of said rotor.

8. A valve for use in a sheet feeding apparatus having a cam shaft supporting cams for moving sheet gripping sucker members, and separating and floating air nozzles and for connecting the sucker members and air nozzles with a source of suction and a supply of air, respectively, comprising, a housing member having air and suction inlet openings and air and suction outlet openings, said air outlet openings adapted to be connected to said air nozzles and said suction outlet openings adapted to be connected to said sucker members, a rotor member mounted on said cam shaft and rotatable in said housing and rotatable at the speed of said cam shaft, said rotor member having a suction chamber constantly communicating with said suction inlet opening so that said suction chamber constantly has a suction applied thereto, means providing a passageway in said rotor communicating said suction chamber with said suction outlet openings upon rotation of said rotor, said rotor member also including an air chamber constantly communicating with said air inlet opening, and means providing a passageway in said rotor for communicating said air chamber with said air outlet openings during a portion of the rotation of said rotor chamber.

9. A sheet feeding apparatus for feeding the topmost sheet of a pile from the pile comprising first suction members operable to grip portions of the topmost sheet, drive means including a first cam means for moving said first suction members generally vertically to raise portions of the sheet, floating air nozzle means for directing a stream of floating air under said topmost sheet and toward the forward end thereof to provide a film of floating air between the topmost sheet and the pile prior to movement of the sheet forwardly, second suction members adapted to grip the sheet and receive the sheet from said first suction members, drive means including second cam means effective to move said second suction members generally forwardly of the pile to move the sheet forwardly of said pile, a cam shaft supporting said first and second cam means and rotatable to effect rotation thereof, sheet advancing means located forwardly of said pile for engaging a sheet moved forwardly and operable to feed a sheet away from the pile, and valve means for conmeeting said floating air nozzle means to a supply of air before said second suction members move said sheet forwardly and for disconnecting said floating air nozzle means and supply of air within 10 of rotation of said ca-m shaft after said second suction members begin moving the sheet forwardly.

10. A sheet feeding apparatus for feeding the topmost sheet of a pile from the pile comprising first suction members operable to grip portions of the topmost sheet, drive means for moving said first suction members generally vertically to raise portions of the sheet, floating air nozzle means for directing a stream of floating air under said topmost sheet and toward the forward end thereof to provide a film of floating air between the topmost sheet and the pile prior to movement of the sheet forwardly, second suction members adapted to grip the sheet and receive the sheet from said first suction members, drive means effective to move said second suction members generally forwardly of the pile to move the sheet forwardly of said pile, sheet advancing means located forwardly of said pile for engaging the leading end of the sheet after the leading end of the sheet has been moved forwardly to a predetermined location and operable to feed a sheet away from the pile, and valve means for connecting said floating air nozzle means to a supply of air before said second suction members move said sheet forwardly and for disconnecting said floating air nozzle means and supply of air before the leading end of said sheet is moved by said second suction members 8% of the total forwarding movement of the sheet by said second suction members.

References Cited bythe Examiner M. HENSON WOOD, JR., Primary Examiner.

20 ROBERT B. REEVES, Examiner. 

1. A SHEET FEEDING METHOD FOR FEEDING THE TOPMOST SHEET OF A PILE FROM THE PILE COMPRISING THE STEPS OF RAISING THE REAR END PORTION OF THE TOPMOST SHEET OF THE PILE TO SEPARATE THE REAR PORTION OF THE SHEET FROM THE PILE, DIRECTING A STREAM THE REAR PORTION OF THE SHEET FROM THE PILE, DIRECTING TOWARD THE FORWARD END THEREOF WHILE THE REAR PORTION OF THE SHEET IS SEPARATED FROM THE PILE, ENGAGING THE REAR END PORTION OF THE SHEET BY FORWARDINLY SUCTION MEMBERS, FEEDING SAID SHEET FORWARDLY OF SAID PILE BY MOVING SAID FORWARDING SUCTION MEMBERS IN A FORWARD DIRECTION AFTER THE STEAM OF FLOATING AIR IS INITIATED, MAINTAINING THE REAR PORTION OF THE SHEET CLEAR OF THE PILE AS IT IS MOVED FORWARDLY, ENGAGING THE FORWARD END OF THE SHEET AFTER THE FORWRD END OF THE SHEET HAS BEEN FED FORWARDLY OF THE PILE TO A PREDETERMINED LOCATION BY MOVEMENT OF SAID FORWARDING SUCTIONMEMBER FOR FEEDING AWAY FROM THE PILE, AND TERMINATING THE FLOW OF SAID FLOATING AIR TOWARD SAID FORWRD END OF THE SHEET BEFORE THE FORWARD END OF THE SHEET IS MOVED BY SAID FORWARDING MOVEMENT OF THE SHEET BY 8% OF THE TOTAL FORWARDING MOVEMENT OF THE SHEET BY SAID FORWARDING SUCTION MEMBERS.
 8. A VALVE FOR USE IN A SHEET FEEDING APPARATUS HAVING A CAM SHAFT SUPPORTING CAMS FOR MOVING SHEET GRIPPING SUCKER MEMBERS, AND SEPARATING AND FLOATING AIR NOZZLES AND FOR CONNECTING THE SUCKER MEMBERS AND AIR NOZZLES WITH A SOURCE OF SUCTION AND A SUPPLY OF AIR, REPSECTIVELY, COMPRISING, A HOUSING MEMBER HAVING AIR AND SUCTION INLET OPENINGS AND AIR AND SUCTION OUTLET OPENINGS, SAID AIR OUTLET OPENINGS AND AIR AND SUCTION OUTLET OPENINGS, SAID NOZZLES AND SAID SUCTION OUTLET OPENINGS ADAPTED TO BE CONNECTED TO SAID SUCKER MEMBERS, A ROTOR MEMBER MOUNTED ON SAID CAM SHAFT AND ROTATABLE IN SAID HOUSING AND ROTATABLE AT THE SPEED OF SAID CAM SHAFT, SAID ROTOR MEMBER HAVING A SUCTION CHAMBER CONSTANTLY COMMUNICATING WITH SAID SUCTION INLET OPENING SO THAT SAID SUCTION CHAMBER CONSTNTLY HAS A SUCTION APPLIED THERETO, MEANS PROVIDING A PASSAGEWAY IN SAID ROTOR COMMUNICATING SAID SUCTION CHAMBER WITH SAID SUCTION OUTLET OPENINGS UPON ROTATION OF SAID ROTOR, SAID ROTOR MEMBER ALSO INCLUDING AN AIR CHAMBER CONSTNTLY COMMUNICATING WITH SAID AIR INLET OPENING, AND MEANS PROVIDING A PASSAGEWAY IN SAID ROTOR FOR COMMUNICATING SAID AIR CHAMBER WITH SAID AIR OUTLET OPENINGS DURING A PORTION OF THE ROTATION OF SAID ROTOR CHAMBER. 